WO2015196261A1

WO2015196261A1 - Tire equipped with ultrasound emiting for water cavitation

Info

Publication number: WO2015196261A1
Application number: PCT/BA2015/000001
Authority: WO
Inventors: Mario SIMILJANIĆ
Original assignee: ZOVKO, Darko
Priority date: 2014-06-26
Filing date: 2015-06-18
Publication date: 2015-12-30
Also published as: DE212015000167U1

Abstract

The ultrasonic tire 1 is the tire having the function of generating ultrasound vibrations on the surface 6 of the tire 1. The piezoelectric ultrasonic generator 4-5 is in charge of generating ultrasound vibrations and is integrated in the crown structure 2 of the tire 1. The piezoelectric ultrasonic generator consists of piezoelectric material 5 and electrodes 4. This innovative tire works in the following way. During emergency braking of the car or when the ABS system is activated, by way of its electrical system the car's central computer unit sends an electrical voltage to the tire 1, or to the piezoelectric ultrasonic generator 4-5 integrated in the internal structure of the crown 2 of the tire 1 causing an immediate ultrasonic mechanical vibration on the surface 6 of the tirel. The tire ultrasonic vibration has the effect of separating the liquid 7 and the surface 6 of the tire 1 resulting in the tire dry tread 8 and 9 of the tire 1 if breaking by car is done on the rain-soaked asphalt 10 (Fig.3). Moreover, when activating the car's ESP system and when targeted braking is performed by an individual wheel, the ultrasonic vibration appears on the surface of that tire by which braking is performed. The same function of this innovative tire may be applied during the activation of ASR system.

Description

TIRE EQUIPPED WITH ULTRASOUND EMITING FOR WATER CAVITATION

1) TECHNICAL FIELD TO WHICH THE INVENTION RELATES

This invention relates to tire, piezoelectric ultrasonic generator, electrical oscillator, rotation sensors and batteries, and according to the International Patent Classification (IPC) is classified as B60C 5/00, B06B 1/06, H01L 41/04, B60T 1/00.

2) TECHNICAL PROBLEM

(The solution of which requires the patent protection)

The friction coefficient a car tire achieves with asphalt is in direct relation to the active car safety. Ideal conditions on the road or asphalt, and those are clean and dry asphalt, allow a car tire to achieve the highest possible friction coefficient with the road or asphalt and thus the car achieves the best possible active safety when moving or stopping.

When water, ice, snow, etc. appears on the asphalt due to various weather conditions, the friction coefficient of a car tire with asphalt decreases significantly and thus the safety of car circulation decreases too. Along with the aforementioned weather conditions various impurities such as sand, mud, etc. can be found on the asphalt, which could also adversely affect the safety of car circulation.

Under the active car safety car we primarily mean the stopping distance while braking and the efficiency of ESP system on a car.

Unlike braking on dry asphalt the stopping distance while braking on wet roadway or asphalt is significantly extended, on average for some 30 to 50%.

Also the efficiency of ESP system whose function is to prevent the car swerving is significantly reduced. 3) BACKGROUND ART

(Display and analysis of known solutions to the defined technical problem)

Solutions to problems such as various unfavorable conditions on the road are of course not entirely possible, but the technical solutions are possible that will aim to reduce the impact of these adverse road conditions on driving and dynamic properties of the car.

One of the solutions to reduce the negative impact of wet-slippery asphalt the car stopping distance while braking is the tire design. The surface part of tire, so-called the crown of tire or part of the tire that makes contact with the asphalt, is designed in such a way that forms longitudinal and transverse grooves and channels used for faster and more efficient drainage of water beneath the tire tread.

Other systems such as the SBC (Sensitive Brake Control) are using highly sophisticated software logarithms, which allow the car the so-called smart braking, in which the optimal braking force, which is aimed at the shortest possible stopping distance, is determined independently for each individual wheel.

4) DISCLOSURE OF THE ESSENCE OF THE INVENTION

(In a manner to enable understanding of technical problem and its solution, and stating technical novelties of invention in comparison with the prior background art)

The primary objective of invention is to provide a tire with the function of the optimization of tread surface during the activation of safety systems.

The secondary objective of invention is to improve driving and dynamic properties of the car.

Additional objectives and advantages of the invention will be partly disclosed in the description that follows, and will be partly find out by the application of invention.

As indicated under paragraph 2 of this disclosure of the invention, one of the biggest problems a car driver may come across during emergency braking is not an optimal situation on the road caused by various weather conditions primarily by rain or wet asphalt.

The above mentioned causes a significant extension of stopping distance and disruption of active safety car features compared to the optimal road condition, and it is clean and dry asphalt. This presumed innovative invention is partly solving the mentioned problem in an innovative way. The idea is to enable the tire with a function of generating ultrasonic vibrations.

The piezoelectric material is selected for the function of generating or creating ultrasonic vibrations on the surface of the tire. Piezoelectric materials such as various types of crystals, ceramics, polymers and their combinations have the possibility of direct transformation of electric energy into a mechanical ultrasonic vibration in their inverse or indirect mode of action. The inverse piezoelectric effect consists in the mechanical deformation of the ultrasonic transducer or generator when it is placed in an electric field, i.e. when it becomes electrified by a certain amount of electricity.

The piezoelectric generator or convertor of ultrasonic vibrations is incorporated into the internal structure of the tire in part of the so-called crown area of the tire. A large majority of pneumatic tires or tires consists of two main parts, and those are the crown of the tire and the sidewalls of tire. The so-called crown of the tire is that part of the tire that makes contact with the base i.e. asphalt. The sidewalls of tire are that part of the tire making contact with the wheel rim and transferring the car weight on the crown of the tire.

The piezoelectric generator of ultrasonic vibrations consists of a material with piezoelectric effect which follows the crown of tire by its shape throughout the length and width of it, electrical voltage electrodes which are connected to both sides of the piezoelectric material i.e. from the upper and lower side of the piezoelectric material and a source of electric power supply. A source of electric power supply of the ultrasonic generator may be a car's electrical system or integrated battery inside the tire.

This presumed innovative tire works in the following way.

During emergency braking of the car or when the ABS system is activated, by way of its electrical system the car's central computer unit sends an electrical voltage to the tire, or to the piezoelectric ultrasonic generator integrated in the internal structure of the crown of tire causing an immediate ultrasonic mechanical vibration on the surface of the tire. The tire ultrasonic vibration has the effect of separating the liquid and the surface of the tire resulting in the tire dry tread if breaking by car is done on the rain-soaked asphalt. Moreover, when activating the car's ESP system and when targeted braking is performed by an individual wheel, the ultrasonic vibration appears on the surface of that tire by which braking is performed. The same function of this innovative tire may be applied when the ASR system is activated. 5) BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included in the description and make the description of the invention, are illustrating the best way of constructing the invention so far.

Fig.l is cross-section of the tire with integrated piezoelectric ultrasonic generator.

Fig.2 is a presentation of the layered structure of the tire with integrated piezoelectric generator.

Fig.3 is a presentation of the interaction of ultrasonic vibrations of the tire with a layer of liquid on the asphalt.

6) DETAILED DESCRIPTION OF AT LEAST ONE BEST MODE FOR CARRYING OUT OF THE INVENTION

Now you will be briefed about the details of this presumed innovative invention one example of which is illustrated in the accompanying drawings.

For understanding the operating mode of the piezoelectric ultrasonic generator 4-5 being integrated in the tire structure 1, it is necessary to explain the basics of ultrasound physics and piezoelectric material 5.

Ultrasound is a sound whose frequency of mechanical waves is above 20 kHz (20000 Hertz). Under mechanical waves we mean the elastic flickering of particles in gaseous, liquid and solid media. As in the above media the particles are interconnected by elastic forces, movement of one particle causes movement of the neighboring particle causing vibration of particles through matter in the direction of propagation of this ph enomenon until the energy of wave movement is consumed. The frequency of vibration or frequency is the number of oscillations performed by particles in a unit of time, i.e. in seconds. The unit for frequency is 1 cycle per second, or 1 Hertz (Hz) for one full oscillation. The expansion rate of vibration from one particle of matter to another is called the speed of sound and depends on the medium or matter where the sound spreads and not due to the frequency of vibration. The speed of sound is different in different media. It is 1450 m/s in the fresh water, while the speedof sound through the medium made of rubber is significantly higher.

Vibrating of particle around its equilibrium position leads to condensation and rarefaction. Occurrences of condensation or rarefaction of the medium alternately are replaced and transferred together with the transfer of the very occurrence of vibration, and are held in alternating change in pressure that exists in the medium in which a sound or ultrasound is produced. Condensation and rarefaction of the medium depends on the elastic deformation caused by mechanical vibration source, in our case it is a piezoelectric material 5. Alternating pressure on the surface 6 of the tire 1 occurs as a cause of vibration. The intensity of power or energy is indicated by decibels in the acoustics of ultrasound. As the ultrasound frequency above 20 kHz is above the range of the human ear, so the intensity of the ultrasound is not a limitation in interacting with people.

Ultrasonic generators or transducers are used for obtaining ultrasound. Ultrasonic generators are transducers of electric power from the power source to ultrasound energy. The basic element of the ultrasonic generator 4-5 is represented by a part that converts electrical energy into ultrasound. It is a characteristic for all ultrasonic generators that they produce ultrasound waves in some medium by mechanical vibration of some suitable elastic system. In that way, for better conversion of electric power to ultrasound one, the resonance is used, that is the mechanical one in the piezoelectric generator.

The transduction ability of the piezoelectric generator 4-5 is characterized by the coupling factor (K). The coupling factor is used to express the ability to convert electrical energy into mechanical energy.

In the piezoelectric generator 4-5 the piezoelectric effect is used for production of ultrasound vibrations. The mentioned effect occurs in piezoelectric materials 5. They possess a very useful combination of electrical and mechanical properties, under the pressure they electrically polarized and vice versa they are deformed under the influence of an electric field. In the piezoelectric material 5 there is a reciprocal connection in both directions between the electrical and mechanical properties. Under the influence of pressure and deformation occurrence there is a voltage on the electrodes 4, direct piezoelectric effect, and deformation and pressure occur on the surrounding environment by the action of electric voltage on the electrodes 4, inverse or indirect piezoelectric effect. The inverse piezoelectric effect is crucial for our innovative ultrasonic or ultrasound tire 1. Deformations occur in all directions of the action of force in the piezoelectric material 5 integrated inside the tire 1. In that way we got a simple, direct and precise mechanism of conversion of electrical energy into mechanical energy

For the observation of the piezoelectric effect, it is necessary that the piezoelectric material 5 acts as a dielectric or insulator. All individual induced dipole moments in the dielectric are directed in the same direction. It can happen that the electric field and potential inside and outside of such dielectric are equivalent to those which would be induced by the existence of surface charge on the dielectric. Such surface charge is called "bound charge". The induced dipoles on the dielectric are manifested as surface charge and vice versa.

For an explanation of the basics of physics the piezoelectric material we will take some nonpolar crystalline dielectric. Since the crystal is non polar, the dipole moments are oriented symmetrically in a way that the total dipole moment of each group of ions disappears. However, if we pressurize the crystal it will happen that a part of the vertical component will remain in the total sum of the dipole moments. As a consequence, in our case, each group of three ions receives some dipole moment, as in the case when the electric field is acted on a non-polar dielectric. We expect the occurrence of the surface charge on the crystal by the same analogy as with the example of the dielectric in the electric field.

The reverse effect, the mechanical deformation of the crystal if the voltage is applied on its surface, is explained in the same way. Then the electric field induces an additional dipole moment contrary to the direction of lines of force of the electric field. Since the system of ions tends towards equilibrium, namely the annulment of the total dipole moment, expansion or contraction of elementary crystal cells takes place, ultimately resulting in mechanical deformation, whose operation is done at the expense of the energy of the electric field originating from the supplied voltage. The mechanical deformation of the piezoelectric material 5 depends on the electrical voltage supplied to the electrodes 4.

Roughly speaking, the piezoelectric generator 4-5 with the supplied voltage of several hundred volts is being deformed for a few hundred micrometers. Depending on the structure and design of the tire itself 1 it is possible to produce a significantly higher deformations on the surface 6 of the tire 1 with the special design of the piezoelectric generator.

The foregoing aims to more efficient separation of layer of liquid 7 on the asphalt 10 from the tire surface 6 in the area of the tread surface 9 and 8 of the tire 1 referring to Fig.3.

The piezoelectric material 5 is designed in such a way that has a very stable and narrowly specified resonant frequency that most effectively rejects the liquid from the surface of tire 1, when the alternating electrical voltage is supplied to the electrodes 4.

Piezoelectric generators made of piezoelectric ceramic material like PZT, various types of piezoelectric polymers such as EAP and ceramic and polymer combinations or their syntheses are the most appropriate for the function of ultrasonic vibration on the surface of tire 6. Moreover, the piezoelectric material may be made also of various types of crystals possessing piezoelectric properties. The fact that each piezoelectric material has its own resonant frequency (or more of them) depending on the form and size of the material is considered in selecting the piezoelectric material. It is also important to take into account that the piezoelectric material has working characteristics such as high operating temperature, low temperature dependence from the resonant frequency and high mechanical strength. Referring to Fig.3 the piezoelectric material is made in the form of strip, which by its dimensions of the width and length follows a circular contour of the crown 2 of the tire 1. Depending on the need, the piezoelectric strip5 may be made in a way that makes one strip, more strips sorted out in layers as well as more discontinuous strips are arranged in such a way to follow the contour of tire 1 parallel to the width.

For the purpose of ultrasound, the piezoelectric material 5 is coated with metal electrodes 4. Metal electrodes 4 may be of silver, chromium or any other suitable material.

The piezoelectric material 5 with metal electrodes 4 is connected with epoxy resin and some other efficient means of connecting. Electrodes 4 are covering front and rear side of the piezoelectric material 5so that between them remains enough space for the thickness o piezoelectric material 5 as well as enough space for ultrasonic vibration of piezoelectric material 5. For the safety from the flashover of sparks, electrodes 4 do not cover the entire surface of the piezoelectric material but only up close to the edge at the distance of several mm. It is also envisaged that the piezoelectric material 5can be made in a single layer or more of them in order to achieve efficiency of the conversion electric energy to the ultrasound vibration on the surface 6 of the tire 1.

Activation of the piezoelectric generator 4-5 is carried out by high frequency electric energy of adequate frequency from the electronic oscillator. The frequency of the electrical voltage coming from the electronic oscillator is harnessed with the resonant frequency of the piezoelectric material 5.The amplitude of the ultrasonic wave will be greatest when the frequency of coercive electric field equals the frequency of oscillation of the piezoelectric material 5, i.e. when the resonance is established. The resonant frequency at which the optimization is performed between the electrical voltage oscillator end the piezoelectric material 5 can be determined in a wider range of ultrasound.

Referring to Fig.l the piezoelectric material 5 with associated electrodes 4 is integrated into the internal structure of the crown 2 of the tire 1 in a way that the piezoelectric device 4-5 is positioned as closer as possible to the surface of tire lfor the purpose of more efficient transmission of ultrasonic vibrations on the surface 6 of the tire 1, as shown on Fig.3, but deep enough into the internal structure of the crown 2 in order to ensure protection against mechanical damage due to movement of tire on the asphalt. Moreover, the piezoelectric generator 4-5 along with the integration inside the crown 2 of the tire 1 is also integrated into that part of the tire 1 where the crown 2 and sidewalls 3 of the tire 1 are connected.

The function of ultrasonic tire 1 or ultrasound tire 1 is creating the ultrasonic mechanical vibrations on the surface 6 of the tire 1.

Ultrasonic vibrations on the surface 6 of the tire 1 have more positive effects for optimization of the car's wheel tread. One of them is to create a sort of protective field generating on the surface 6 of the tire 1 which prevents the contact of liquid 7 and the tire 1 primarily in the area in front of the tread 9 and the tread 8. The protective field is a result of the effect of transmission of ultrasonic vibrations from the surface 6 of the tire 1 to the surrounding air molecules that are in direct contact with the surface 6 of the tire 1.

In addition, the ultrasonic mechanical vibration generated on the surface of tire creates the so-called cavitation.

Cavitation is the effect when the molecular bonds of liquids begin to break down due to strong mechanical vibrations, in our case due to ultrasonic vibrations on the surface of tire. Under the action of ultrasound similar occurrences take place in liquids as in the heating. If ultrasonic vibrations, produced in a liquid or in the immediate vicinity, are strong enough to produce a change in pressure, higher than atmospheric pressure in liquids, then a, voltage will be created during vibrations which will break down the medium of intermolecular bonds and resulting in a sudden formation of bubbles in the fluid as well as in the heating. When completely cool water is exposed to the activity of ultrasound, it begins to evaporate rapidly as when the water reaches its highest boiling point.

As already mentioned in the description of this invention, in order that generator produces an ultrasound vibration it necessary to be connected to a source of power supply. A source of power supply can be the car's electrical system or battery integrated into a suitable part of the tire or the wheel rim. In the case when a source is the car's electrical system, then the piezoelectric generator 4-5 is connected by cables to the car via a wheel rim. Connecting the electric cables of the tire or the rim to the cables of car's electrical system is performed by the induction method or the electromagnetic induction.

If the battery is the source of electrical voltage, the ultrasonic tire needs to be equipped also with a rotation sensor through which the battery would know when to supply electricity to the piezoelectric generator. In that case rotation sensors are registering a sudden decelerations or accelerations, and sending the activation for the flow of current. When the source of power supply is the car's electrical system, the ultrasonic tire 1 is significantly cheaper and easier to make since there is no need for battery and sensors since electronic components already integrated into the car's system are used.

The ultrasonic tire is activated during sudden braking or activation of the ABS system. Also, during activation of ESP and ASR systems.

When the car performs a sudden braking that is when the ABS system is activated, the central computer unit sends a signal to the car's electrical system to release the electric voltage to electrodes 4 which are an integral part of the piezoelectric generator being integrated into the tire 1 together with the piezoelectric material 4. Due to the action of electrical current passing through the piezoelectric material 5 through electrodes 4, the piezoelectric generator momentarily generates powerful ultrasonic mechanical vibrations on the surface 6 of the tire 1. The ultrasonic vibration of tire has the effect of separating the liquid 7 and the surface 6 of the tire 1, resulting in dry tire tread 8 and 9 if the braking by car is done on the slippery asphalt 10 or on the roadway soaked by rain. The above mentioned results in a significant reduction of the stopping distance while braking by car in the rain.

During activation of ESP and ASR systems the piezoelectric generator causes ultrasonic vibrations on the surface of that tire by which is performed the targeted individual braking (ESP) or increased the coefficient of friction of the drive wheels (ASR).

As already stated, the piezoelectric ultrasonic generator 4-5 is integrated into the crown structure 2 of the tire 1 and thereby the possibility is left that the piezoelectric ultrasonic generator is installed on a rim. When the ultrasonic generator 4-5 is directly installed on a rim then ultrasound vibrations are spreading on the surface 6 of the tire 1 through the rim and sidewalls 3 of the tire 1.

7) MODE OF APPLICATION OF THE INVENTION

In the above manner the invention enables the car to optimize the wheel tread while braking (ABS) and during the activation of ESP and ASR systems.

The entire system consists of parts that can effectively be installed and connected in the tire and car as one unit.

The innovative system finds its application in the automotive industry.

It will be self-evident to experts that some modifications to the system can be made according to this invention, without leaving the scope and essence of the invention.

Claims

PATENT CLAIMS

1. The ultrasonic tire 1 with integrated piezoelectric generator 4-5 of ultrasound vibrations, characterized in that the piezoelectric generator 4-5 of ultrasound vibrations integrated into the crown structure 2 of the tire 1 (Fig.l) generates the ultrasound vibration on the surface 6 of the tire 1 during emergency braking or activation of ESP and ASR systems (Fig. 3). The piezoelectric ultrasonic generator consists of electrodes 4 and piezoelectric material 5. The function of electrodes 4 is to provide electric energy to the piezoelectric material 5 based on which the piezoelectric material performs ultrasound vibrations.

2. The ultrasonic tire 1 with integrated piezoelectric generator 4-5 of ultrasound vibrations according to the claim, characterized in that the piezoelectric ultrasonic generator 4-5 is connected by cables to the car's electrical system using the induction method.

3. The ultrasonic tire 1 with integrated piezoelectric generator 4-5 of ultrasound vibrations according to the claim, characterized in that the piezoelectric ultrasonic generator 4-5 is connected to the battery of electrical voltage being integrated into the tire 1 or the rim. Battery is equipped with rotation sensors.

4. The ultrasonic tire 1 with integrated piezoelectric generator 4-5 of ultrasound vibrations according to the claim, characterized in that the piezoelectric ultrasonic generator 4-5 is installed on the car's wheel rim.

Mario Smiljanic